2-Trifluoromethyl-3,3,3-trifluoropropene is an interesting compound as a monomer for production of various polymers. For instance, it is copolymerized with vinylidene fluoride to produce a vinylidene fluoride/2-trifluoromethyl-3,3,3-trifluoropropene alternating copolymer having good heat resistance (Japanese Patent Publication No. 28210/1984). Further, for instance, its incorporation as a monomeric unit into an ethylene/tetrafluoroethylene copolymer produces marked improvement in physical properties (Japanese Patent Publication No. 25806/1984).
For production of said 2-trifluoromethyl-3,3,3-trifluoropropene, there has been known a process wherein hexafluoroacetone and acetic anhydride or ketene are subjected to pyrolysis (Japanese Patent Publication No. 35168/1983). However, this process is industrially disadvantageous, because hexapluoroacetone as the starting material is quite expensive and drastic conditions are required for the pyrolysis. There has also been known a process wherein octafluoroisobutyl lower alkyl ether is dehydrofluorinated, the resulting heptafluoroisobutenyl lower alkyl ether is reduced to hexafluoroisobutyl lower alkyl ether, and the latter is sulfated to produce hexafluoroisobutyl lower alkyl sulfate, which is then treated with a base to give 2-trifluoromethyl-3,3,3-trifluoropropene (Japanese Patent Publication No. 6133/1982). Apparently, this process requires many steps and necessitates the use of various reagents and equipments.